Table 1.
Characteristics of Participants.
| All participants (n = 77) | Participants WPPSI performed (n = 31) | Participants WPPSI not performed (n = 46) | P value | |
|---|---|---|---|---|
| Maternal demographic data | ||||
| Age, y, mean | 29.2 ± 6.4 | 26.5 ± 6.1 | 31.0 ± 5.9 | .002 |
| Married status*, n (%) | .144 | |||
| Single | 32 (41.6) | 17 (54.8) | 15 (32.6) | |
| Married | 35 (45.5) | 12 (38.7) | 23 (50.0) | |
| Maternal race or ethnicity*, n (%) | .313 | |||
| Black | 41 (53.3) | 18 (58.1) | 23 (50.0) | |
| White | 30 (39.0) | 11 (35.5) | 19 (41.3) | |
| Asian | 1 (1.3) | 0 (0) | 1 (2.2) | |
| Hispanic | 2 (2.6) | 2 (6.5) | 0 (0) | |
| Maternal education*, n (%) | .157 | |||
| < High school | 19 (24.7) | 11 (35.5) | 8 (17.4) | |
| 2 years college | 9 (11.7) | 2 (6.5) | 7 (15.2) | |
| 4 years college | 18 (23.4) | 8 (25.8) | 10 (21.7) | |
| Graduate level | 10 (13.0) | 2 (6.5) | 8 (17.4) | |
| Infant birth data | ||||
| Gender | .250 | |||
| Male | 39 (50.7) | 13 (41.9) | 26 (56.5) | |
| Female | 38 (49.4) | 18 (58.1) | 20 (43.5) | |
| Gestational age, wk | 28.1 ± 2.5 | 28.4 ± 2.5 | 28.0 ± 2.4 | .464 |
| Birthweight, g | 1164 ± 384 | 1132 ± 357 | 1170 ± 395 | .554 |
| Multiple gestation, n (%) | 29 (37.7) | 14 (45.2) | 15 (32.6) | .339 |
| Small for gestational age, n (%) | 2 (2.60) | 1 (3.23) | 1 (2.17) | 1 |
| Infant race or ethnicity, n (%) | .786 | |||
| Black | 41 (53.3) | 18 (58.1) | 23 (50.0) | |
| White | 35 (45.5) | 13 (41.9) | 22 (47.8) | |
| Hispanic | 0 (0) | 0 (0) | 0 (0) | |
| Asian | 1 (1.3) | 0 (0) | 1 (2.2) | |
| Neonatal risk factors | ||||
| Bronchopulmonary dysplasia*, n (%) | 8 (10.4) | 6 (19.4) | 2 (4.4) | .059 |
| Intraventricular hemorrhage grade 3 or 4*, n (%) | 3 (3.9) | 1 (3.2) | 2 (4.4) | 1 |
| Necrotizing enterocolitis*, n (%) | 5 (6.5) | 2 (6.5) | 3 (6.5) | 1 |
| Patent ductus arteriosus ligation*, n (%) | 10 (13.0) | 4 (12.9) | 6 (13.0) | 1 |
| Retinopathy of prematurity requiring laser treatment,* n (%) | 3 (3.9) | 2 (6.5) | 1 (2.2) | .563 |
| Sepsis*, n (%) | 13 (16.9) | 6 (19.4) | 7 (15.2) | .762 |
| Length of stay*, d | 72.1 ± 68.9 | 65.1 ± 87.0 | 77.1 ± 53.2 | .467 |
| Postnatal steroids*, n (%) | 9 (11.7) | 4 (12.9) | 5 (10.9) | 1 |
| Mechanical ventilation*, n (%) | 49 (63.6) | 22 (71.0) | 27 (58.7) | .837 |
| Later risk factors | ||||
| Hearing loss*, n (%) | 6 (7.8) | 2 (6.5) | 4 (8.7) | .681 |
| Blindness, n (%) | 0 (0) | 0 (0) | 0 (0) | 1 |
| Major neurologic abnormality*, n (%) | 7 (9.1) | 1 (3.2) | 6 (13.0) | .227 |
| Autism*, n (%) | 3 (3.9) | 2 (6.5) | 1 (2.2) | .602 |
| Receiving EI*, n (%) | 52 (67.5) | 30 (96.8) | 22 (47.8) | 1 |
| Study characteristics | ||||
| Corrected age in months at BSID-II | 19.2 ± 2.9 | 19.6 ± 1.8 | 18.9 ± 3.5 | .300 |
| Corrected age in months at Bayley-III* | 18.7 ± 2.4 | 19.4 ± 1.7 | 18.3 ± 2.7 | .040 |
| Age in months at WPPSI | 47.4 ± 11.4 | 47.4 ± 11.4 | N/A | N/A |
Data are presented as mean ± SD or No. of %.
*
Data analyzed included those for whom the outcome was known. Number missing for married status (10), maternal race (3), maternal education (21), BPD (2), IVH (2), NEC (4), PDA (2), ROP (1), sepsis (2), length of stay (2), postnatal steroids (9), mechanical ventilation (5), hearing loss (9), major neurologic abnormality (4), autism (12), received EI (23), age in months at Bayley-III (2).